車架結(jié)構(gòu)動(dòng)力學(xué)仿真

1、課程名稱結(jié)構(gòu)動(dòng)力學(xué)仿真實(shí)驗(yàn)名稱車架結(jié)構(gòu)的動(dòng)力學(xué)仿真分析姓名學(xué)號導(dǎo)師實(shí)驗(yàn)組別同實(shí)驗(yàn)者評定成績審閱教師實(shí)驗(yàn)報(bào)告要目實(shí)驗(yàn)?zāi)康膶?shí)驗(yàn)要求實(shí)驗(yàn)軟硬件實(shí)驗(yàn)方法步驟實(shí)驗(yàn)結(jié)果實(shí)驗(yàn)討論、實(shí)驗(yàn)?zāi)康?.掌握幾何建?；痉椒?.掌握模態(tài)分析、頻響分析和瞬態(tài)分析的一般性流程3.掌握如何用分析結(jié)果的圖形化顯示方法，并進(jìn)行結(jié)果分析二、實(shí)驗(yàn)要求如圖所示中空對稱結(jié)構(gòu)（以G、A中點(diǎn)和L、F中點(diǎn)連線為對稱軸），L和F端固定在剛性墻上。采用殼單元建模，通過有限元分析，計(jì)算該結(jié)構(gòu)的動(dòng)力學(xué)特征和在特定激勵(lì)下的動(dòng)響應(yīng)。Units;mmW仁加3W2=1,182L1=1,518L2=865Sizeofrectangularhollowbeam:

2、53x111to53x191dependingonlocations.Thicknessofshell;3.5L3=927L4=3611）計(jì)算該結(jié)構(gòu)的前10階固有模態(tài)。2）假設(shè)模態(tài)阻尼比為0.003，在A端外廓處作用垂直于紙面的單位正弦激勵(lì)，計(jì)算A、G端外廓處的加速度響應(yīng)頻響函數(shù)和位移頻響函數(shù)。（3）若A端外廓處作用的載荷為三角形沖擊載荷，載荷幅值為100N，三角形沖擊載荷的脈沖寬度為3ms，計(jì)算計(jì)算A、G端外廓處的加速度響響應(yīng)和位移響應(yīng)。（材料楊氏模量為210GPa,泊松比為0.3，密度為7890kg/m3。）三、實(shí)驗(yàn)軟硬件計(jì)算機(jī)型號：華碩A45V；配置：顯卡類型：入門級獨(dú)立顯卡;顯存容量：

3、2GB；CPU主頻：2.3GHz核心數(shù)：四核心/八線程軟件名稱：patran2010和Nastran2010四、實(shí)驗(yàn)方法步驟1.模態(tài)分析新建名為mode.db的模型文件，并選擇MSC.Nastran進(jìn)行結(jié)構(gòu)分析File/NewFilename=chejia.db/OK/AnalysisCode=MSC.Nastran/AnalysisType=Structural/OK調(diào)整patran單位制Preference/Geometrygeometryscalefactor=1000.0(Milimeters)從外部文件導(dǎo)入名為chejia.igs的幾何模型(CATIA作圖)File/ImportOb

4、ject=Model/Source=IGES/文件名=chejia.igs/Apply/Ok劃分單元網(wǎng)格，網(wǎng)格類型為4節(jié)點(diǎn)四邊形單元(Quad4),全局單元邊長取10Elements/Action=Create/Object=Mesh/Type=Surface/ElemShape=Quad/Mesher=Paver/Topolgy=Quad4/SurfaceList=Surface1:24/GlobalEdgeLength=10/Apply網(wǎng)格去重Action=Equivalence/Object=All/Method=ToleranceCube/EquivalencingTolerence=

5、0.005/Apply創(chuàng)建材料屬性。彈性模量210Gp，泊松比0.3，密度7890kg/m3Materials/Action=Create/Object=Isotropic/Method=ManualInput/MaterialName=steel/InputProp.ElasticModulus=210e6/PoissonRatio=0.3/Density=7890e-9/OK/Apply(注意：本文件單位制采用mm,因此此處彈性模量和密度需要作出相應(yīng)的單位轉(zhuǎn)換)創(chuàng)建單元屬性。殼單元厚度為3.5mmProperties/Action=Create/Object=2D/Type=Shell/P

6、ropertySetName=shell/InputProp.MaterialName=steel/Thickness=3.5/OK/SelectAppli.ApplicationRegion=Surface1:24/Add/OK/Apply備份.db文件，方便后續(xù)頻響分析以及瞬態(tài)分析File/Saveacopy./文件名=frequency.db；File/Saveacopy./文件名=time.db；定義約束條件。車架L,F端固定Loads/BCs/Action=Create/Object=Displacement/Type=Nodal/NewSetName=fix/inputDataTr

7、anslations=/Rotations=/OK/SelectAppli.Select=Geometry/ApplicationRegion=Surface1、5/Add/OK/Apply定義分析類型并進(jìn)行分析Analysis/Action=Analyze/Object=EntireModel/Method=FullRun/SolutionTypeSolutionType=NORMALMODES/OK/Subcases/SubcaseName=Default/SubcasePara.NumberofDe.=10/OK/Apply/Apply讀取計(jì)算結(jié)果并觀察各階振型Action=Access

8、Results/Object=AttachXDB/Method=ResultEntities/selectresultsfiles=chejia.xdb/ApplyResults/Action=Create/Object=QuickPlot/SelectRe.=Default,A1:Mode:./SelectFri.=Eigenvectors,./Quantity=Magnitude/SelectDe.=Eigenvectors,./Apply2.頻響分析打開備份文件frequency.db進(jìn)行頻響分析File/open/文件名=frequency.db創(chuàng)建載荷工況Load/BCs/Creat

9、eLoadCases/Action=Create/LoadCaseName=case1/MarkCurrent(選中)/Type=TimeDependent/LoadCaseScaleFactor=1.0/Apply創(chuàng)建非空間場Field/Action=create/Object=nonspatial/Method=TabularInput/FieldName=freq/ActiveIndependentVariables=Frequency/Inputdata/f-1=1/value=1/f-2=200/value=1/OK/Apply創(chuàng)建位移約束及單位正弦載荷。車架L,F端固定，A點(diǎn)加單位

10、正弦激勵(lì)Loads/BCs/Action=Create/Object=Displacement/Type=Nodal/NewSetName=fix/inputDataTranslations=/Rotations=/OK/SelectAppli.Select=Geometry/ApplicationRegion=Surface1、5/Add/OK/ApplyLoads/BCs/Action=Create/Object=Force/Type=Nodal/NewSetName=force1/InputDataLoad/BCSetScaleFactor=1.0/Force=/Time/Freq.De

11、pendence=f:freq/Ok/SelectApplicationRegionSelect=FEM/ApplicationRegion/SelectNodes=Node43760(NodeA)/Add/Ok/Apply定義分析類型并設(shè)置分析參數(shù)Analysis/Action=Analyze/Object=EntireModel/Method=FullRun/Jobname=frequency/SolutionTypeSolutionType=FREQUNCYRESPONSE/Formulation=Direct/SolutionPara.Struct.DampingCoeff.=0.00

12、3/OK/OK定義分析工況Subcases/SubcaseName=case1/SubcasePara.DEFINEFREQUENCIES.StartFreq.=0;EndFreq=300;No.Incr=300/OK/OK/OutputRequestsOutputRequests=DISPLACEMENT;ACCELERATION/OK/Apply/Cancel提交分析工況SubcaseSelect.SubcaseSelected=case1/OK/Apply讀取計(jì)算結(jié)果并觀察頻率響應(yīng)函數(shù)圖像Action=AccessResults/Object=AttachXDB/Method=Resul

13、tEntities/selectresultsfiles=frequency.xdb/ApplyResults/Action=Create/Object=Graph/SelectResultCases=case1.-filter/Apply/SelectYResult=Accelerations/Displacements/Quantity=Magnitude/TargetEntities/SelectNodes=NodeA、G/Apply3.瞬態(tài)分析1)打開備份文件frequency.db進(jìn)行瞬態(tài)分析File/open/文件名=time.db創(chuàng)建載荷工況Load/BCs/CreateLoad

14、Cases/Action=Create/LoadCaseName=case2/MarkCurrent(選中)/Type=TimeDependent/LoadCaseScaleFactor=1.0/Apply創(chuàng)建非空間場Field/Action=create/Object=nonspatial/Method=TabularInput/FieldName=time/ActiveIndependentVariables=Time/Inputdata/t-1=0/value=0/t-2=0.0015/value=1/t-3=0.003/value=0/t-4=0.01/value=0/OK/Apply

15、創(chuàng)建位移約束及三角脈沖載荷。車架L,F端固定，A點(diǎn)加三角脈沖激勵(lì)Loads/BCs/Action=Create/Object=Displacement/Type=Nodal/NewSetName=fix/inputDataTranslations=/Rotations=/OK/SelectAppli.Select=Geometry/ApplicationRegion=Surface1、5/Add/OK/ApplyLoads/BCs/Action=Create/Object=Force/Type=Nodal/NewSetName=force2/InputDataLoad/BCSetScaleFa

16、ctor=1.0/Force=/Time/Freq.Dependence=f:time/Ok/SelectApplicationRegionSelect=FEM/ApplicationRegion/SelectNodes=Node43760(NodeA)/Add/Ok/Apply定義分析類型并設(shè)置分析參數(shù)。Analysis/Action=Analyze/Object=EntireModel/Method=FullRun/Jobname=time/SolutionTypeSolutionType=TRANSIENTRESPONSE/Formulation=Direct/OK定義分析工況。Subc

17、ases/SubcaseName=case2/SubcasePara.DEFINETIMESTEPS.No.ofTimeSteps.=400;Delta-T=0.0005/OK/ModalDamping=Crit.Damp.(CRIT)/DEFINEMODALDAMPING/Frequency=0,Value=0.003/Frequency=500.Value=0.003/OK/OK/OutputRequestsOutputRequests=DISPLACEMENT;ACCELERATION/OK/-Apply-/Cancel提交分析工況。SubcaseSelect.SubcaseSelect

18、ed=case2/OK/Apply讀取計(jì)算結(jié)果并觀察響應(yīng)函數(shù)圖像。Action=AccessResults/Object=AttachXDB/Method=ResultEntities/selectresultsfiles=time.xdb/ApplyResults/Action=Create/Object=Graph/SelectResultCases=case2.-filter/Apply/SelectYResult=Accelerations/Displacements/Quantity=Magnitude/TargetEntities/SelectNodes=NodeA、G/Apply

19、五、實(shí)驗(yàn)結(jié)果1.前十階模態(tài)Mode1Mode2Mode3Mode4Mode6Mode7Mode8Mode9Mode102.頻響分析LEGENDNode10602:Accelerations,Translational,MAGroUOQe_suel-SUOQeooov9.00+000-7.50+000-6.00+000-1.50+000-3.00+000-1.50+000-A點(diǎn)加速度耦合頻響曲線LEGEND_euoQe_suel-SUOQe21.50+000-1.50+00050+0003.00+000-3.00+00050+000A點(diǎn)加速度X方向頻響曲線LEGEND .00-005.00-00

20、4.0IMICH3.00-002.00-001.00-00_euoQe_suel-S4Uujoe_dsoLEGENDA點(diǎn)位移耦合頻響曲線6.00-004.50-0CH3.00-00-3.00-001.50-00-1.50-00_euoQe_sueJ_-srEoe_dsQA點(diǎn)位移X方向頻響曲線LEGEND9.00+0007.50+0006.00+0001.50+0003.00+0001.50+0000.5.00+0011.00+0021.50+0022.00+0022.50+0023.00+002FrequencyNode9077:Accelerations,Translational,MAGcuUOQe_suel-suo一ro00ovG點(diǎn)加速度耦合頻響曲線LEGENDeuoQesuel-SUOQe28.00-00-6.00-001-00-0CM-2.00-0CM-0.-2.00-0CM-400-00!o.5.00+0011.00+0021.50+0022.00+0022.50+0023.00+002FrequencyG點(diǎn)位移X方向頻響曲線3.瞬態(tài)分析（取0.003阻尼比）G點(diǎn)加速度X方向頻響曲